For one of the older, more iconic hotels in Las Vegas, I was not impressed with their rooms or casino. The rooms were a bit dated, however I only stayed in a basic suite.
The restaurants, however, are nothing short of amazing. With Robuchon's first ever US based restaurant residing next to the Ka Theater, there is a plethora of dining options. I tend to lean towards the gourmet dining scene while I am at MGM, because anything else would be a waste of time.
There are also a few great bars located throughout MGM...so if you have time to kill and want a great drink at Vegas prices, make sure to hit up Centrifuge next to the Poker Room.